A headlamp device for lighting a forward area of a two-wheeled motor vehicle or a motorcycle is disposed at a distinguishable part in a front part of a vehicle body. Since it is a part that can be viewed from outside, a headlamp device is required to have an aesthetic aspect or aestheticity. A headlamp device with improved aestheticity as applied to a motorcycle is disclosed in, e.g., Japanese Patent Application Laid-Open Publication No. 2004-82851 (JP-A 2004-82851).
In the motorcycle disclosed in JP-A 2004-82851, a headlamp stay extends forward from a front suspension of the motorcycle. A lower headlamp case is attached to the headlamp stay. A lamp unit is inserted into the lower headlamp case from above and secured to the headlamp stay. Then, an upper headlamp case is laid on the lower headlamp case with the lamp unit enclosed therein. Since the headlamp stay is enclosed by the upper and lower headlamp cases, a resultant headlamp device has improved external looks.
However, since the headlamp case is comprised of two parts, namely, the upper headlamp case and the lower headlamp case, the headlamp device has an increased number of parts, rendering the device complex in construction.
Moreover, an operation to mount the headlamp device to the motorcycle body comprises three steps, namely, the lower headlamp case mounting step, the lamp unit mounting step, and the upper headlamp case mounting step. Since the three steps are required to mount the headlamp device to the motorcycle body, the headlamp device mounting operation is tedious and complex.